In a semiconductor device manufacturing process using the photolithography technique, for example, a resist coating treatment of applying a resist solution onto a film to be etched on a wafer surface to form a resist film, exposure processing of exposing a predetermined pattern on the resist film on the wafer, a developing treatment of developing the exposed resist film on the wafer to form a resist pattern, an etching treatment of etching a base film using the resist pattern as a mask and so on are performed in order.
Incidentally, in recent years, to further miniaturize the circuit pattern, an exposure technology is being employed which uses an exposure light source with a short wavelength of 193 nm or less, such as an ArF laser, F2 laser, or the like. Therefore, it is necessary to use a material corresponding to the exposure light source with a short wavelength for a resist solution to be supplied onto the wafer surface.
However, the resist solution corresponding to a light with a short wavelength of 193 nm or less has a relatively low etch resistance and may have been etched together with the base film during the etching treatment. Accordingly, the dimensions of a groove and a hole to be finally formed in the base film are larger than the expected dimensions, failing to stably form a circuit pattern of a desired dimension.
Development of the resist material is proceeding to improve the etch resistance of the resist pattern but has limits, and sufficient etch resistance has not been realized. Besides, a method of forming a resist pattern is proposed in which photosensitive light is applied to the entire resist patter and the resist pattern is then baked during process of the wafer processing to improve the etch resistance (for example, see Patent Document 1).
However, the above-described method is directed to the resist pattern having a benzene ring corresponding to the exposure light source with a wavelength of 250 nm or longer, and therefore does not present a sufficient effect for a resist pattern corresponding to the exposure light source with a short wavelength of 193 nm or less.
Patent Document
Japanese Patent Application Laid-open No. H6-69118